I have used a feeding bowl and have had excellent results with it. My chameleon knows its feeding time as soon as she sees me take the cup to get crickets and wax worms(i use a plactic pint container that some wonton soup came in at a chinease resturant
...it dishwasher safe and easy to clean) Also with a cup or bowl, you know that your chameleon is eating, and can keep track of how much they eat. Some people like to just let the crickets run around they cage and have the chameleon hunt for them. But i have had problems with this because, as you said, dense foliage. I aslo have a wire screen cage that I built for her, and the darn bugs never stay in there.
But as for waiting or buying...hmmmmnnn well. I would buy a veiled, save up while waiting for the rainbow, and get him/her too! lol i wish...i'm broke. but I hope you can decide.
Kaitlyn